[Eliezer]

One must acquire the habit of thinking on the margins. If there are millions of people and billions of dollars attacking problem A which kills millions of people, and dozens of people and hundreds of thousands of dollars attacking problem B which kills millions of people, ceteris paribus your next marginal dollar is likely to have a bigger impact on B.

With that said, my own efforts are going into AI, not aging; the negative side of AI (recursive self-improvement by an agent with non-human-aligned goals) is something that, for all we know in this epistemic state, could happen at literally any time (hidden NSA lab finally achieved AI a month ago, it improved to superintelligence a week ago, cracked the protein folding problem, emailed some DNA strings to protein synthesis labs, got nanotechnology an hour ago, whoops we're all dead).

So if you're one of those people for whom problems don't exist unless they at least might destroy your self of tomorrow and not just your self of thirty years from now, I actually am spending my time on one of those problems.

But mostly I regard immediate temporal proximity as an invalid constraint on philanthropy.